Method of and furnace for coating pipes with metal



Dec. 27, 1938. M. BRAUN METHOD OF AND FURNACE FOR COATING PIPES WITH METAL Filed June 2, 1937 s Sheets-Sheet 1 5y a fld I f 7 A ffor'neyd" Dec. 27, 1938. M. BRAUN METHOD OF AND FURNACE FOR COATING PIPES WITH METAL Filed June 2, 1957 I s Sheets-Sheet 2 Fig.3 415) /n venzor:

ME B n BJVWVIM W A orney M. BRAUN Dec. 27, 1938.

METHOD AND FURNACE FOR COATING PIPES WITH METAL Filed June 2, 1957 3 Sheets-Sheet s Ma lus Bra n.

I A zz arw yo' Patented Dec. 27,

UNITED STATES METHOD OF AND FURNACE FOR COATING I PIPES WITH METAL Matthias Bral m, mammalian-Maia,-

w Germany Application June 2, 1937, Serial m. mama In Germany June it, 19%

For this purpose the furnaceis provided with' a heating chamber having astepped-bottom, and means are provided for rolling the pipes along It) said bottom by pushing them from one step on to another. Means are also provided for tilting the pipes in order to discharge superfluous coatcooling pro.cesS.-

Fig, 1 of the accompanying drawings repreing metal, and for cooling the pipes after the sents a sectional view, of a furnace constructed according to the invention. I

Fig. 2 is a section at right angles to Fig- 1, Fig. 3 is a section on the line 3-3 of Fig. 2, Fig. 4 is a diagram showing a modification of the stepped bottom of the heating chamber, and

Fig. 5 is a sectional view likeFig. 1 showing a modified arrangement.

The furnace is providedwith a heating cham- .25 her theinlet to which is permanently closed in order to prevent loss ,of heat and in order to retain the protecting gas which maintains the heated pipes in polished condition. The closing element consists of a feeding roller a which is 80 rotatably fitted in the inlet and provided with longitudinal grooves b in which the pipes are placed for. introduction by means of a roller into the heating chamber. *The roller forms a complete closure of the inlet even when it is 35.rotated. The pipes f are delivered by the roller on to a platformc which is wide enough to hold several pipes at the same time. The platform 0 is developed into a stepped chamber bottom down regards vertical and horizontal'dimensions, as

indicated in Fig. 4. This is of advantageas 5o regards uniformity of the coating since it ensures that "the pipes will drop on to the steps with different bearing surfaces and prevent the'molten .metalfrom accumulating continually alonglthe same pipe portion.

, -55 I The chamber is preferably by means (on. iii-412.2

'.-of electric heating elements h, but it can also be adapted for heating by means of gas or solid fuel. 1

After having rolled through the heating chamber in this manner, the pipes are brought into an inclined position for the discharge therefrom of superfluous coating metal. For this purpose the pipes are discharged from the last step ainto a downwardly inclined channel It. This channel containsan inclined roller 1 which receives the pipes, 'tilts them through an angle of about 90 and delivers them in this position into' an inclined delivery channel 711.. The roller 2 is hollow and cooled so that ,the temperature of the pipes will fall rapidly below the melting point of thecoating metal. A conveyor n is arranged so as to receive the pipes from the delivery channel and place them once more in a horizontal position. The conveyor moves the pipes slowly through the furnace while still under the influence-of the protecting gas and delivers them, after they have been subjected to further cooling, into a water bath .of normal temperature. There may be two separately fed heating chambers in the same furnace arranged as indicated in Fig. 3. I

When the pipes are to be provided with a parvticularly thick coating, they are charged with 1 the required quantity of coating metal, and means are provided for using up all the metal in the coating. For this purpose the arrangement shown in Fig. '5 may be employed. In this arrangement the heating chamber is adjoined by" a cooling chamber p provided'with an inclined delivery plane (1. 'The first portion of the cool-' ing chamber is comparatively hot, but the succeeding portion of the planeis exposed to cooling sprays r of water or air so that the coating metal will be caused to solidify. Owing to the continuous rolling motion of the pipes, the 00817". ing will be uniiormthroughout. .Uniformity of coating is particularly necessary when the pipes are subsequently to be subjected to a drawing operation. x

From the; plane q the'pipes are delivered into a drum 3 which is open 'at the top and which. clips with its lower portion into a water bath t. In this drumv thepipes are subjected to further cooling. and when the drum contains a suitable number of pipes it is rotated; for discharging the pipes into the bath t for final cooling,

' In order to maintain thepipe surfaces free from corrosion, the 'entirefurnace system is charged with a protecting'gas'. -Wh i1e.the inlet is permanently closed by the roller 11, the outlet ture of the invention is that the bottom of the heating chamber is stepped and that the pipes are fed intermittently from one step on to another. The number of stepsis dependent on the desired efficiency. of the furnace, the greater the number of steps the greater will be the efflciency.

I claim:

1. A method of coating pipes internally with metal comprising subjecting the pipes internally charged with coating metal to heat sumcient to melt the coating metal and simultaneously rolling said pipes in horizontal position and intermittently down a series of approximately vertical positions to cause the molten coating metal to apply itself uniformly over the interior of saidpipes.

2. A method of coating pipes internally with metal comprising subjecting'jthe pipes internally charged with coating metal to temperature sufficient to melt said coating 'metal, intermittently rolling said pipes while they are exposed to said heat in horizontal position down a series of approximately vertical positions to cause the molten coating metal to apply itself uniformly over the interior of the pipes, tilting the pipes out of horizontal position to drain oif surplus molten coating metal, and subjecting the pipes to further rolling in horizontal position while they are exposed to a somewhat lower temperature.

. 3. A method of coating pipes internally with metal comprising subjecting the pipes internally charged with coating metal to a temperature s ufiicient to melt said coating metal, intermittently rolling said pipes while they are exposed to said heat in horizontal position down a series of approximately vertical positions to cause the molten coating metal to apply itself uniformly over the interior of the pipes, and subjecting the pipes to further rolling in horizontal position and to simultaneous cooling to solidify the coating.

4. An oven for internally coating pipes with molten metal comprising a chamber extending obliquely downwardly through the oven, ;said' chamber having its bottom formed with a series or steps capable of supporting the pipes, means for introducing the pipes charged internally with coating metal and in horizontal positiononto the uppermost step of the chamber bottom, means acting intermittently and transversely to the pipes on said steps to roll the pipes to the edges of the steps whereby they fall ,by gravity from one step to the next, means for subjecting the pipes to heat'above the fusion heat of the coating metal while the pipes are rolling down said steps, and means for discharging the pipes from thelowermost step to the outside of' the oven.

5. An oven for internally coating pipes with molten metal comprising a chamber extending obliquely downwardly through the oven, said chamber having its bottom formed with a series of stepscapable of supporting the pipes, means for introducing the pipes charged internally with.

coating metal and in horizontal position onto the uppermost step'of the chamber bottom, means channel.

of the steps whereby they fall by gravity from one step to the next, means-for subjecting the pipes to heat above the fusion heat of the coating metal while the pipes are rolling down said steps, an inclined channel below said steps, and an inclined roller arranged to receive the pipes from the lowermost step, tilt said pipes out of horizontal position and direct them into the 6. An oven for internally coating pipes with molten metal comprising a chamber extending obliquely downwardly through the oven, said chamber having its bottom formed with a series of steps capable of supporting the pipes, means for introducing the pipes charged internally with coating metal and in horizontal position onto the uppermost step of the chamber bottom, means acting intermittently and. transversely to the pipes on said steps to roll the pipes to the edges of the steps whereby they fall by gravity from one step to the next, means for subjecting the pipes to heat above the fusion heat of the coating metal while the pipes are rolling down said steps, an inclined channel below, said steps, an

inclined roller arranged to receive the pipes from the lowermost step, tilt said pipes'out of horizontal position and direct them into the channel, and a horizontal conveyor below the channel arranged to receive the pipes and carry them in horizontal position out of the oven.

7. An oven for internally coating pipes with molten metal comprising a chamber extending obliquely downwardly through the oven, said chamber having its bottom formed with a series of steps capable of, supporting the pipes, means for introducing the pipes charged internally with coating metal and in horizontal position onto the uppermost step of the chamber bottom, means acting intermittently and transversely to the pipes on said steps to roll the pipes to the edges of the steps whereby they fall by gravity from one step to the next, means for subjecting the pipes 'to heat above the fusion heatof the coating metal while the pipes are rolling down said steps, an inclined channel below said steps, an inclined roller arranged to receive the pipes from the lowermost step, tilt said pipes out of horizontal position and direct them into the channel, and means for cooling the inclined roller.

8. An oven for internally coating pipes with molten metal comprisinga chamber extending obliquely downwardly through the oven, said chamber having its bottom formed with a series of steps capable of supporting the pipes, means for introducing the pipes charged internally with coating metal and in horizontal position onto the uppermost step of the chamber bottom, means acting intermittently and transversely to the pipes on said steps to roll the pipes to the edges of the steps whereby they fall by gravity from one step to the next, means for subjecting the steps, a cooling chamber communicating with the lower end of the'oblique chamber and having its floor substantially continuous with and downwardly .inclined from the bottom of the lowermost step, means for cooling said inclined chamber floor, and means for discharging pipes from thelower end of said floor to the outside of the oven. 4 1

MAT'I'HAUS BRAUN. 

